CN117700694A

CN117700694A - Cross-linked polymer, binder, ionic membrane, and preparation method and application thereof

Info

Publication number: CN117700694A
Application number: CN202311365612.6A
Authority: CN
Inventors: 何庆一; 姚进; 张侨侨; 于志伟
Original assignee: Ningbo Zhongke Hydrogen Easy Film Technology Co ltd
Current assignee: Ningbo Zhongke Hydrogen Easy Film Technology Co ltd
Priority date: 2023-10-20
Filing date: 2023-10-20
Publication date: 2024-03-15
Anticipated expiration: 2043-10-20
Also published as: CN117700694B

Abstract

The application provides a cross-linked polymer, a binder, an ionic membrane, a preparation method and application thereof, and relates to the technical field of hydrogen production by water electrolysis, wherein adjacent polyphenyl units in the cross-linked polymer react with CF through ketone precursors ₃ -C-B bonding, CF ₃ -C-B is a monomerEach polyphenyl unit comprises a group after the reaction of a benzene precursor and a first group, wherein the first group is a group after the reaction of a ketone precursor and a counter ion, the group after the reaction of the ketone precursor provides positive ions, and the counter ion is any one of iodide ions, bromide ions, chloride ions, hydroxide ions and bicarbonate ions; or the first group is a group obtained after the ketone precursor reacts, and the group obtained after the ketone precursor reacts is the residual group obtained after the indoloquinone removes one carbonyl oxygen. Therefore, the ionic membrane based on the cross-linked polymer has lower swelling rate, higher mechanical property, better hydrophilicity and better alkali resistance stability.

Description

Cross-linked polymer, binder, ionic membrane, and preparation method and application thereof

Technical Field

The application relates to the technical field of hydrogen production by water electrolysis, in particular to a cross-linked polymer, a binder, an ionic membrane, a preparation method and application thereof.

Background

The anion exchange membrane electrolyzed water (anion exchange membrane water electrolyzer, AEMWE) technology integrates the advantages of the traditional alkaline electrolyzed water technology and the proton exchange membrane electrolyzed water technology, and has great application potential. Anion Exchange Membranes (AEMs) are key components therein, capable of serving as hydrogen (H) ₂ ) And oxygen (O) ₂ ) And ion transport. The traditional AEM material is mainly made of linear polymer, and the performance of the electrolytic tank is often reduced due to swelling in the operation process of the electrolytic tank, for example, AEM is excessively swelled in the electrolytic tank, the local pressure bearing capacity is possibly weakened in the fluid mass transfer process, and AEM is possibly partially damaged in the long-term operation process, so that the overall operation efficiency is reduced; alternatively, the AEM may be excessively swollen to deteriorate its binding ability with the catalyst, and as the operation time increases, the catalyst may be severely dropped, thereby causing the overall performance of the electrolytic cell to be deteriorated.

Crosslinking is one of the effective methods for inhibiting the swelling of the film, and the current crosslinking method is, for example, 1, adding a crosslinking agent in the resin synthesis process to directly obtain a crosslinked resin, and then processing the crosslinked resin into a film; 2. after the anion exchange membrane resin material is obtained, adding a cross-linking agent, performing cross-linking reaction to crosslink the anion exchange membrane resin material, and then dissolving, drying and forming a film of the crosslinked resin; 3. after the anion exchange membrane is obtained, adding a cross-linking agent solution on the surface of the formed membrane, and gradually diffusing the cross-linking agent solution to realize the crosslinking in the membrane. The core of these processes is the addition of a crosslinking agent, which, although simple and convenient, has obvious disadvantages. Disadvantages of the external crosslinker include: influence the polymerization reaction, so that the polymerization reaction is difficult to be carried out efficiently; the dissolubility of the ionic resin is deteriorated, and the processing difficulty is increased; the permeation crosslinking on the surface of the membrane is difficult to control the uniformity of crosslinking, so that the membrane performance is difficult to reproduce; the reaction degree is difficult to control, and the processing difficulty is increased.

Therefore, in order to improve the stability of the AEMWE cell, it is desirable to develop a low swelling, high mechanical strength AEM to solve the above problems.

Disclosure of Invention

The embodiment of the application provides a cross-linked polymer, a binder, an ionic membrane, a preparation method and application thereof, so that the problems of high swelling rate, low mechanical strength, poor alkali resistance stability and poor performance of an electrolytic cell of a traditional ionic membrane can be solved.

In order to achieve the above purpose, the embodiments of the present application adopt the following technical solutions:

in one aspect, a crosslinked polymer is provided that includes a plurality of polyphenylic units, one polyphenylic unit reacted with a CF via a ketone precursor ₃ -C-B is bonded to another polyphenylic unit, said CF ₃ -C-B is bonded to the nitrogen atom of the group after reaction with the ketone precursor, wherein CF ₃ -C-B is a monomerThe residual structure after the reaction is any one of alkyl, alkoxy, a structure with at least one benzene ring and derivatives thereof, heterocyclic structures and derivatives thereof, and X is a halogen atom;

each polyphenyl unit comprises a group after the reaction of a benzene precursor and a first group, wherein the first group at least comprises a group after the reaction of a ketone precursor, the group after the reaction of the benzene precursor has at least three phenyl groups, and two adjacent groups with the phenyl groups are bonded through the group after the reaction of the ketone precursor;

The first group is a group after the ketone precursor reacts and a counter ion, the group after the ketone precursor reacts provides positive ions, and the counter ion is any one of iodide ions, bromide ions, chloride ions, hydroxide ions and bicarbonate ions;

or the first group is a group after the ketone precursor reacts, and the group after the ketone precursor reacts is the residual group after the indoloquinone removes one carbonyl oxygen.

Further, in the case that the first group is a group after the reaction of the ketone precursor and a counter ion, the ketone precursor is an N-methyl-4-piperidone monomer;

alternatively, in the case where the first group is a group after the reaction of the ketone precursor, the ketone precursor is an indoloquinone monomer.

Further, in the case where the ketone precursor is an N-methyl-4-piperidone monomer, the crosslinked polymer has a structural formula of:

alternatively, in the case where the ketone precursor is an indoloquinone monomer, the crosslinked polymer has a structural formula of:

ar is a group after the benzene precursor reacts, and the benzene precursor is any one of biphenyl, p-terphenyl, tetrabiphenyl, 9, 10-biphenylanthracene, m-terphenyl, 1,3, 5-triphenylbenzene, fluorene and 1, 4-diphenoxybenzene;

The B is any one of a long alkyl chain with a chain length of 1-10, an alkoxy chain with a chain length of 1-10, a structure with at least one benzene ring and a derivative thereof, a heterocyclic structure and a derivative thereof;

n is the molar ratio, and the value of n is between 0 and 0.1;

x is the counter ion.

wherein CF3-C-B is a monomerAnd the structure remained after the reaction, wherein the B is any one of long alkyl chain with the chain length of 1-10, alkoxy chain with the chain length of 1-10, benzene ring and derivatives thereof, biphenyl and derivatives thereof, pyridine and derivatives thereof, quinoline and derivatives thereof, tropane and derivatives thereof, phenothiazine and derivatives thereof, furan and derivatives thereof.

Further, the saidIncluding 3-bromo-1, 1-trifluoroacetone or 2, 2-trifluoro-4' -Xiuji acetophenone.

In another aspect, a binder is provided comprising the crosslinked polymer described above, the crosslinked polymer being untreated.

In yet another aspect, an ionic membrane is provided comprising the crosslinked polymer described above, the crosslinked polymer being treated.

In yet another aspect, an electrolytic cell is provided comprising an anode, a cathode, and a membrane electrode assembly disposed between the anode and the cathode;

The membrane electrode assembly comprises the binder, the catalyst and the ionic membrane, wherein the binder is used for binding the catalyst to the surface of the ionic membrane.

In yet another aspect, a method for preparing the ionic membrane is provided, including the following steps:

synthesizing a cross-linked polymer;

preparing the crosslinked polymer into a slurry;

and placing the slurry on a support, and drying after strickling to obtain the ionic membrane.

Further, the synthetic cross-linked polymer includes:

adding DMmol benzene reaction precursor, xmmol ketone precursor, (D-X) mmol trifluoro ketone compound and EmL dichloromethane into a reactor; wherein D and X are positive integers, D is larger than X, the value range of X is 0-30mmol, and the value range of E is 50-100mL;

dropwise adding FmL trifluoroacetic acid and/or GmL trifluoromethanesulfonic acid, and keeping the reaction system at a first temperature for reacting for a first time to obtain a product; wherein the value range of F is 10-50mL, the value range of G is 50-100mL, the value range of the first temperature is-5-10 ℃, and the value range of the first time is 18-120h;

the product is immersed in water, washed by alkali liquor with first concentration, then dissolved in an organic solvent, and heated and crosslinked at a second temperature to obtain the crosslinked polymer; wherein the value range of the first concentration is 0.5-1.5M, and the value range of the second temperature is 30-120 ℃.

Further, the configuring the crosslinked polymer into a slurry includes:

dissolving the first weight of the crosslinked polymer in a solvent with a first volume, filtering and defoaming to obtain the slurry; wherein the value range of the first weight is 1-15g, and the value range of the first volume is 95-150mL.

Further, the step of placing the slurry on a support, and drying after the slurry is scraped to obtain the ionic membrane comprises the following steps:

and pouring the slurry on a glass plate, and drying after scraping by a scraper to obtain the ionic membrane.

Embodiments of the present application provide a crosslinked polymer obtained from a precursor having multiple functionalities through a self-crosslinking reaction, specifically, a linear polymer itself is micro-crosslinked under a heat treatment to form the crosslinked polymer of the present application. Therefore, the ionic membrane formed by the cross-linked polymer has the advantages of low swelling rate, high mechanical property, high hydrophilicity, high alkali resistance stability and the like, and the electrolytic water performance of the electrolytic tank based on the ionic membrane is high.

The foregoing description is only an overview of the technical solutions of the present application, and may be implemented according to the content of the specification in order to make the technical means of the present application more clearly understood, and in order to make the above-mentioned and other objects, features and advantages of the present application more clearly understood, the following detailed description of the present application will be given.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of an electrolytic cell according to an embodiment of the present disclosure;

fig. 2 is a schematic view of polarization curves of the ion membranes of example 1 and comparative example 1 provided in the examples of the present application after application to an electrolytic cell.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved by the present application more clear, the present application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

In this application, the term "and/or" describes an association relationship of an association object, which means that there may be three relationships, for example, a and/or B may mean: a alone, a and B together, and B alone. Wherein A, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship.

In the present application, "at least one" means one or more, and "a plurality" means two or more. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (individual) of a, b, or c," or "at least one (individual) of a, b, and c" may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c or a-b-c, wherein a, b, c may be single or multiple, respectively.

It should be understood that, in various embodiments of the present application, the sequence number of each process does not mean that the sequence of execution is sequential, and some or all of the steps may be executed in parallel or sequentially, where the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

The terminology used in the embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The weights of the relevant components mentioned in the embodiments of the present application may refer not only to specific contents of the components, but also to the proportional relationship between the weights of the components, and thus, any ratio of the contents of the relevant components according to the embodiments of the present application may be enlarged or reduced within the scope disclosed in the embodiments of the present application. Specifically, the mass described in the specification of the examples of the present application may be a mass unit known in the chemical industry such as μ g, mg, g, kg.

The terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated for distinguishing between objects such as substances from each other. For example, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX, without departing from the scope of embodiments of the present application. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

In a first aspect, embodiments herein provide a crosslinked polymer comprising a plurality of polyphenylic units, one polyphenylic unit reacted with a CF via a ketone precursor ₃ -C-B is bonded to another polyphenylic unit, CF ₃ -C-B is bonded to the nitrogen atom of the group after reaction with the ketone precursor.

Wherein CF is as follows ₃ -C-B is a monomerThe structure remaining after the reaction, B is any one of an alkyl group, an alkoxy group, a structure having at least one benzene ring and derivatives thereof, a heterocyclic structure and derivatives thereof. X is a halogen atom.

Each polyphenyl unit comprises a group after the reaction of a benzene precursor and a first group, wherein the first group at least comprises a group after the reaction of a ketone precursor, the group after the reaction of the benzene precursor has at least three phenyl groups, and two adjacent groups with phenyl groups are bonded through the group after the reaction of the ketone precursor.

The first group is a group obtained after the reaction of the ketone precursor and a counter ion, wherein the group obtained after the reaction of the ketone precursor provides positive ions, and the counter ion is iodide (I) ^- ) Bromide ion (Br) ^- ) Chloride ion (Cl) ^- ) Hydroxide ion (OH) ^- ) Bicarbonate ion (HCO) ₃ ^- ) Any one of them.

Or the first group is a group obtained after the ketone precursor reacts, and the group obtained after the ketone precursor reacts is the residual group obtained after the indoloquinone removes one carbonyl oxygen.

The benzene precursor is not particularly limited, and may include any of biphenyl, p-terphenyl, tetrabiphenyl, 9, 10-biphenylanthracene, m-terphenyl, 1,3, 5-triphenylbenzene, fluorene, 1, 4-diphenoxybenzene, and the like, by way of example.

The ketone precursor is not particularly limited, and in an exemplary case, the ketone precursor may be a ketone precursor that provides a positive ion, for example, N-methyl-4-piperidone, or the like. In another case, the ketone precursor may be an indoloquinone.

For the above-mentioned trifluoroketone compoundWithout being particularly limited, exemplary, trifluoroketonesMay include->Etc.

Further, the method comprises the steps of,may include 3-bromo-1, 1-trifluoroacetone or 2, 2-trifluoro-4' -Xiuji acetophenone, etc.

The above X is not particularly limited, and exemplified are fluorine (F) atom, chlorine (Cl) atom, bromine (Br) atom, iodine (I) atom, etc.

The present application is directed to the above CF ₃ B in C-B is not particularly limited, and may be a long alkyl chain (chain length 1-10) when B is an alkyl group; when B is an alkoxy group, it may be a long alkoxy chain (chain length 1-10); when B is benzene, benzene ring, biphenyl, terphenyl, p-terphenyl, m-terphenyl, tetraphenyl and the like and derivatives thereof can be used; when B is a heterocyclic ring, it may be pyridine, quinoline, tropane, phenothiazine, furan, or a derivative thereof, for example, a derivative obtained by introducing an alkyl substituent at least one of the ortho, meta, or para positions of benzene.

It is understood that the crosslinked polymer can be formed by self-crosslinking of benzene precursors, ketone precursors, and trifluoroketone compounds under certain conditions by friedel-crafts reaction.

After obtaining the linear polymer, the linear polymer needs to be subjected to heat treatment to cause micro-crosslinking of the linear polymer, so as to obtain the micro-crosslinked ionic resin, namely the ionic membrane.

In addition, the micro-crosslinking of self molecules and molecules can be realized by adjusting the proportion of monomers such as benzene precursors, ketone precursors, trifluoroketone compounds and the like, and the crosslinking degree can be controlled.

The present embodiments provide a cross-linked polymer obtained from a precursor having a multi-functionality through a self-crosslinking reaction, specifically, a linear polymer itself is micro-crosslinked under a heat treatment to form the cross-linked polymer of the present application. Therefore, the ionic membrane formed by the cross-linked polymer has the advantages of low swelling rate, high mechanical property, high hydrophilicity, high alkali resistance stability and the like, and the electrolytic water performance of the electrolytic tank based on the ionic membrane is high.

Further, in the case where the first group is a group after the reaction of a ketone precursor and a counter ion, the ketone precursor is an N-methyl-4-piperidone monomer.

Further, in the case where the first group is a group after the reaction of the ketone precursor, the ketone precursor is an indoloquinone monomer.

Further, in the case where the ketone precursor is an N-methyl-4-piperidone monomer, the crosslinked polymer has the structural formula:

ar is a group obtained after a benzene precursor reacts, and the benzene precursor is any one of biphenyl, p-terphenyl, tetrabiphenyl, 9, 10-diphenylanthracene, m-terphenyl, 1,3, 5-triphenylbenzene, fluorene and 1, 4-diphenoxybenzene; b is a long alkyl chain having a chain length of 1-10, an alkoxy chain having a chain length of 1-10, a structure having at least one benzene ring, a derivative thereof, or a heterocyclic structureAnd any of its derivatives; n is the molar ratio, and the value of n is between 0 and 0.1; x is a halogen atom.

Further, in the case where the ketone precursor is an indoloquinone monomer, the crosslinked polymer has the structural formula:

ar is a group obtained after a benzene precursor reacts, and the benzene precursor is any one of biphenyl, p-terphenyl, tetrabiphenyl, 9, 10-diphenylanthracene, m-terphenyl, 1,3, 5-triphenylbenzene, fluorene and 1, 4-diphenoxybenzene; b is any one of a long alkyl chain with a chain length of 1-10, an alkoxy chain with a chain length of 1-10, a structure with at least one benzene ring and derivatives thereof, a heterocyclic structure and derivatives thereof; n is the molar ratio, and the value of n is between 0 and 0.1.

Further, in the case where the ketone precursor is an N-methyl-4-piperidone monomer, the crosslinked polymer has the general structural formula:

wherein CF is as follows ₃ -C-B is a monomerThe structure remaining after the reaction, B is any one of a long alkyl chain with a chain length of 1-10, an alkoxy chain with a chain length of 1-10, a benzene ring and a derivative thereof, biphenyl and a derivative thereof, pyridine and a derivative thereof, quinoline and a derivative thereof, tropane and a derivative thereof, phenothiazine and a derivative thereof, and furan and a derivative thereof.

It will be appreciated that the above-mentioned polyphenylic units are monopolymer segments, each monopolymer segment having the structure a+b+c form, wherein a is a group having a phenyl group, b is a first group, c is a monomerStructure CF remaining after reaction ₃ -C-B. Furthermore, the monomers are polymerizedThe bond between the compound chain segment and the single polymer chain segment is also realized through a trifluoro ketone compound.

The above-mentioned N-containing ⁺ Is obtained by reacting N-methyl-4-piperidone.

In a second aspect, embodiments of the present application provide a binder comprising the crosslinked polymer described above, wherein the crosslinked polymer is untreated.

The present embodiments provide a binder that is an untreated cross-linked polymer, specifically, a linear polymer that is micro-crosslinked upon itself under heat treatment to form the binder.

In a third aspect, as shown in fig. 1, an embodiment of the present application provides an ionic membrane 13 comprising the crosslinked polymer described above.

The ionic membrane provided by the embodiment of the application is a processed cross-linked polymer, the cross-linked polymer enables the linear polymer to be micro-cross-linked under heat treatment, and after the cross-linked polymer is formed, the ionic membrane is obtained after treatment. Therefore, the ionic membrane formed by the cross-linked polymer has the advantages of low swelling rate, high mechanical property, good hydrophilicity, good alkali resistance stability and the like, and the electrolytic water performance of the electrolytic tank based on the ionic membrane is good.

In a fourth aspect, as shown in fig. 1, an embodiment of the present application provides an electrolytic cell 10 including an anode 11, a cathode 12, and a membrane electrode assembly disposed between the anode 11 and the cathode 12.

The membrane electrode assembly includes the above-described binder (not shown in fig. 1), a catalyst (not shown in fig. 1), and the above-described ion membrane 13, and the binder is used to bind the catalyst to the surface of the ion membrane 13.

It should be noted that the electrolytic cell 10 shown in fig. 1 further comprises deionized water/lye 14 and a battery 15. Wherein, the deionized water is liquid deionized water; the alkali solution may be 1M potassium hydroxide (KOH), but may be other alkali solutions, and is not particularly limited herein.

In fig. 1, deionized water/alkali solution is introduced into the anode side and the cathode side, but the present invention is not limited thereto. For example, it is also possible to provide only the cathode side with deionized water/lye and the anode side without deionized water/lye, in which case an electrolytic cell can also be constructed.

According to the electrolytic tank provided by the embodiment of the application, the ionic membrane is formed by the cross-linked polymer, so that the ionic membrane has the performances of low swelling rate, high mechanical property, good hydrophilicity, good alkali resistance stability and the like, and the electrolytic tank based on the ionic membrane shows excellent water electrolysis performance.

In a fifth aspect, an embodiment of the present application provides a method for preparing the ionic membrane.

The preparation method comprises the following steps:

s1, synthesizing a cross-linked polymer.

S2, preparing the crosslinked polymer into slurry.

And S3, placing the slurry on a support, and drying after scraping to obtain the ionic membrane.

In the step S3, the slurry is placed on a support, scraped and dried to obtain the ionic membrane, and the preparation method may further include:

s4, mixing the cross-linked polymer with a catalyst, and coating the mixture on the surface of the ionic membrane to form the electrode in the electrolytic cell.

According to the preparation method of the ionic membrane, the micro-crosslinking of self molecules and molecules is achieved through the regulation and control of the self groups of the target polymer. Thus, on one hand, the influence of the external cross-linking agent on polymerization is avoided; on the other hand, the method can be realized without complex crosslinking processing, and greatly simplifies the reaction steps; on the other hand, the crosslinking degree can be controlled by adjusting the proportion of the monomers, so that the swelling of the ionic membrane can be effectively inhibited on the premise of ensuring the solubility of the product, and the mechanical property of the ionic membrane is improved. The micro-crosslinking ionic membrane prepared by the method has excellent mechanical properties, and can be assembled into an electrode by using a binder made of resin with the same component as the ionic membrane, so that the stability in an electrolytic cell is obviously improved.

Further, the step S1 of synthesizing the crosslinked polymer includes:

s11, adding DMmol of benzene reaction precursor, xmmol of ketone precursor, (D-X) mmol of trifluoro ketone compound and EmL of dichloromethane into a reactor.

Wherein, D and X are positive integers, D is larger than X, the value range of X is 0-30mmol, and the value range of E is 50-100mL.

The ketone precursor may be N-methyl-4-piperidone or indoloquinone.

S12, dropwise adding FmL trifluoroacetic acid and/or GmL trifluoromethanesulfonic acid, and keeping the reaction system at a first temperature for reacting for a first time to obtain a product.

Wherein, the value range of F is 10-50mL, the value range of G is 50-100mL, the value range of the first temperature is-5-10 ℃, and the value range of the first time is 18-120h.

S13, the product is immersed in water, washed by alkali liquor with a first concentration, then dissolved in an organic solvent, and heated and crosslinked at a second temperature to obtain the crosslinked polymer.

Wherein the range of the first concentration is 0.5-1.5M, and the range of the second temperature is 30-120 ℃.

In the case that the ketone precursor is N-methyl-4-piperidone, the step S13 is to sink the product in water, wash the product with alkali solution of a first concentration, dissolve the product in an organic solvent, and crosslink the product by heating at a second temperature to obtain a crosslinked polymer, which comprises:

s14, the product is immersed in water, washed by alkali liquor with a first concentration, then dissolved in an organic solvent, heated and crosslinked at a second temperature, and finally dried, and then the residual piperidine is ionized by treatment with a compound containing counter ions, thus obtaining the crosslinked polymer.

The benzene-based reaction precursor is not particularly limited, and may include any of biphenyl, p-terphenyl, tetrabiphenyl, 9, 10-biphenylanthracene, m-terphenyl, 1,3, 5-triphenylbenzene, fluorene, 1, 4-diphenoxybenzene, and the like, by way of example.

N-methyl-4-piperidone may provide a positive ionic group.

The value of D is not particularly limited, and exemplary values of D may range from 80 to 100. Specifically, the value of D may be 80, 90, 100, or the like.

The value of X is not particularly limited, and may be, for example, 0, 10, 20, 30, or the like.

It should be noted that, the ionic membrane with different properties can be obtained by changing the value of D, X to obtain different crosslinked polymers.

The above-mentioned methylene chloride may be used as a solvent. The volume fraction of the above-mentioned methylene chloride is not particularly limited, and E may be, for example, 50, 60, 70, 80, 90, 100, or the like.

The above trifluoroacetic acid can be used to improve the acidity of the reaction system. The volume fraction of the above trifluoroacetic acid is not particularly limited, and exemplified, F may be 10, 20, 30, 40, 50 or the like.

The volume fraction of the trifluoromethanesulfonic acid is not particularly limited, and G may be, for example, 50, 60, 70, 80, 90, 100, or the like.

The first temperature is not particularly limited, and may be, for example, -5 ℃, -3 ℃, -1 ℃, 4 ℃, 7 ℃, 10 ℃ or the like.

The first time is not particularly limited, and may be, for example, 18h, 20h, 40h, 70h, 90h, 120h, or the like.

The counter ion is I ^- 、Br ^- 、Cl ^- 、OH ^- 、HCO ₃ ^- In this case, the corresponding counter ion-containing compound is methyl iodide solution, potassium bromide solution, potassium chloride solution, potassium bicarbonate solution, or potassium hydroxide solution, respectively.

The type of the above lye is not particularly limited, and illustratively, the lye may include potassium chloride (KCl), sodium chloride (NaCl), potassium bromide (KBr), sodium bromide (NaBr), potassium hydroxide (KOH), sodium hydroxide (NaOH), potassium carbonate (k) ₂ CO ₃ ) Carbon (C)Sodium (Na) ₂ CO ₃ ) Potassium bicarbonate (KHCO) ₃ ) Sodium bicarbonate (NaHCO) ₃ ) And the like.

The first concentration of the above-mentioned lye is not particularly limited, and may be, for example, 0.5M, 0.8M, 1M, 1.2M, 1.5M or the like. By setting a suitable lye concentration, the product can be subjected to a more thorough treatment.

The ionic membrane provided by the embodiment of the application realizes micro-crosslinking of the connection of the self frameworks through the regulation and control of the self groups of the target polymer. Thus, on one hand, the influence of the external cross-linking agent on polymerization is avoided; on the other hand, the method can be realized without complex crosslinking processing, and the experimental steps are greatly simplified; on the other hand, the crosslinking degree is controllable by adjusting the proportion of the monomers, so that the swelling of the membrane is inhibited and the mechanical property is improved on the premise of ensuring the solubility of the product. The micro-crosslinking ionic membrane obtained in this way shows excellent mechanical properties, and can also be assembled into an electrode by using a binder prepared from resin with the same components as the ionic membrane, so that the stability in an electrolytic cell is obviously improved.

Further, the step S2 of preparing the crosslinked polymer into a slurry includes:

s21, dissolving the first weight of the crosslinked polymer in a solvent with a first volume, filtering and defoaming to obtain slurry.

Wherein the value range of the first weight is 1-15g, and the value range of the first volume is 95-150mL.

The first weight is not particularly limited, and may be, for example, 1g, 3g, 5g, 8g, 10g, 15g, or the like.

The first volume is not particularly limited, and exemplary, the first volume may be 95mL, 100mL, 110mL, 120mL, 130mL, 140mL, 150mL, or the like.

In practical use, the type of the above-mentioned solvent is not particularly limited, and exemplified by at least one of dimethyl sulfoxide (DMSO), azomethide (DMF), azomethide acetamide (DMAC), azomethide pyrrolidone (NMP), and the like.

Further, in the step S3, placing the slurry on a support, and drying after strickling, the method for obtaining the ionic membrane includes:

s31, pouring the slurry on a glass plate, and drying after scraping by a scraper to obtain the ionic membrane.

The following provides a specific preparation process of the first ionic membrane:

1. the synthesis steps of the crosslinked polymer are as follows:

step S01, adding 90mmol of benzene reaction precursor, xmmol of N-methyl-4-piperidone, (90-X) mmol of trifluoro ketone compound, 50-100mL of dichloromethane solvent, 10-50mL of trifluoroacetic acid and 50-100mL of trifluoromethanesulfonic acid into a three-neck flask dropwise, and keeping the reaction system at-5-10 ℃ for 18-120h.

Wherein x=0-30.

Step S02, sinking the product in water, 1M lye wash (including but not limited to KOH, naOH, na ₂ CO ₃ 、K ₂ CO ₃ 、NaCHO ₃ ) The method comprises the steps of carrying out a first treatment on the surface of the Then the product is dissolved in an organic solvent and heated at 30-120 ℃ to cause the product to be micro-crosslinked; then the residual piperidine is ionized by treatment with methyl iodide (MeI) after the precipitation and drying, and the counter ion is I ^- 。

Conversion to Br ^- 、Cl ^- 、OH ^- 、HCO ₃ ^- It is only required to soak it in KBr, KCl, KOH, KHCO ₃ And (3) the solution is obtained.

2. The preparation steps of the crosslinked polymer slurry are as follows:

step S03, dissolving 1-15g of crosslinked polymer in 100mL of dimethyl sulfoxide (DMSO) or azodicarbonamide (DMF) or azodicarbonamide (DMAc) or azomethylpyrrolidone (NMP), filtering, and defoaming to obtain slurry.

3. The preparation method of the ionic membrane comprises the following steps:

and S04, pouring the defoamed slurry on a glass plate, and drying after scraping by a scraper to obtain the self-crosslinking polymer ionic membrane.

The preparation method of the ionic membrane is simple and easy to realize.

The following provides a specific preparation process of the second ionic membrane:

1. the synthesis steps of the crosslinked polymer are as follows:

step S01, adding 90mmol of benzene reaction precursor, xmmol of indoloquinone, (90-X) mmol of trifluoro-ketone compound, 100-150mL of dichloromethane solvent, 5-50mL of trifluoroacetic acid and 100-150mL of trifluoromethanesulfonic acid into a three-neck flask dropwise, and keeping the reaction system at-5-10 ℃ for 24-120h.

Wherein x=0-30.

S02, sinking the product in water, washing with ethanol, and drying; then the product is dissolved in an organic solvent and heated at 30-120 ℃ to cause the product to be micro-crosslinked.

2. The preparation steps of the crosslinked polymer slurry are as follows:

3. The preparation method of the ionic membrane comprises the following steps:

The preparation method of the ionic membrane is simple and easy to realize.

The ionic membranes of the embodiments of the present application and methods of making and using the same are illustrated below by a number of specific examples.

Example 1

Into a three-necked flask, 90mmol of biphenyl, 85mmol of N-methyl-4-piperidone, 5mmol of 3-bromo-1, 1-trifluoroacetone and 60mL of methylene chloride were charged. 2mL of trifluoroacetic acid and 60mL of trifluoromethanesulfonic acid were added dropwise, and the reaction was carried out at room temperature for 72 hours. And then the product is immersed in water, washed and dried. Dissolving 50g of the dried product in DMSO, crosslinking at 80deg.C for 5h, precipitating, adding 50g of MeI, reacting for 24h to ionize, washing, oven drying, and standing at 1M Soaking in KOH solution for 48 hr to convert counter ion into OH ^- And cleaning and drying again to obtain the crosslinked polymer.

10g of the crosslinked polymer was dissolved in 100mL of DMAc, and the solution was filtered and defoamed to obtain a slurry.

And taking a clean horizontal glass plate, pouring the slurry on the surface of the glass plate, scraping by a scraper, and then placing the glass plate in an oven to dry for 12 hours at 95 ℃ to obtain the micro-crosslinking ionic membrane.

Example 2

Into a three-necked flask, 90mmol of p-terphenyl, 87mmol of N-methyl-4-piperidone, 3mmol of 3-bromo-1, 1-trifluoroacetone and 120mL of methylene chloride were charged. 120mL of trifluoromethanesulfonic acid and 20mL of trifluoroacetic acid are added dropwise and reacted for 24 hours at room temperature. Dissolving 50g of the dried product in DMSO, crosslinking at 60 ℃ for 12 hours, precipitating the product, drying, dissolving 30g of the dried product in DMSO, adding 50g of MeI for reaction for 48 hours to ionize the product, wherein the counter ion is I ^- Washing, oven drying, soaking in 1M KOH solution for 24 hr to convert counter ion into OH ^- And cleaning and drying again to obtain the crosslinked polymer.

10g of the crosslinked polymer was dissolved in 100mL of DMSO, and the solution was filtered and defoamed to obtain a slurry.

And taking a clean horizontal glass plate, pouring the slurry on the surface of the glass plate, scraping by a scraper, and then placing the glass plate in an oven to dry at 100 ℃ for 24 hours to obtain the micro-crosslinking ionic membrane.

Example 3

Into a three-necked flask, 90mmol of m-terphenyl, 83mmol of N-methyl-4-piperidone, 7mmol of 2, 2-trifluoro-4' -Xiuji acetophenone and 100mL of methylene chloride were charged. 100mL of trifluoromethanesulfonic acid was added dropwise and reacted at 0℃for 72 hours. And then the product is immersed in water, washed and dried. Dissolving 20g of the dried product in DMAc, crosslinking at 60 ℃ for 24 hours, precipitating the product, drying, adding 50g of MeI for reaction for 24 hours to ionize the product, wherein the counter ion is I ^- Washing, oven drying, soaking in 1M KOH solution for 24 hr to convert counter ion into OH ^- And cleaning and drying again to obtain the crosslinked polymer.

10g of the crosslinked polymer was dissolved in 100mL of DMF, and the solution was filtered and defoamed to obtain a slurry.

And taking a clean horizontal glass plate, pouring the slurry on the surface of the glass plate, scraping by a scraper, and then placing the glass plate in an oven to dry for 12 hours at 80 ℃ to obtain the micro-crosslinking ionic membrane.

Example 4

Into a three-necked flask, 90mmol of fluorene, 85mmol of N-methyl-4-piperidone, 5mmol of 3-bromo-1, 1-trifluoroacetone and 80mL of methylene chloride were charged. 5mL of trifluoroacetic acid and 80mL of trifluoromethanesulfonic acid were added dropwise. The reaction was carried out at-10℃for 24h. And then the product is immersed in water, washed and dried. Dissolving 20g of the dried product in DMSO, crosslinking at 75 ℃ for 48 hours, precipitating the product, drying, dissolving 50g of the dried product in DMF, adding 50g of MeI for reaction for 48 hours to ionize the product, wherein the counter ion is I ^- Washing, oven drying, soaking in 1M KOH solution for 24 hr to convert counter ion into OH ^- And cleaning and drying again to obtain the crosslinked polymer.

Example 5

Into a three-necked flask, 90mmol of biphenyl, 85mmol of indoloquinone, 5mmol of 3-bromo-1, 1-trifluoroacetone and 120mL of methylene chloride were charged. 5mL of trifluoroacetic acid and 120mL of trifluoromethanesulfonic acid were added dropwise, and the reaction was carried out at room temperature for 24 hours. And then the product is immersed in water, washed and dried. And dissolving 15g of the dried product in DMSO, crosslinking for 8 hours at 65 ℃, precipitating the product, cleaning and drying to obtain the crosslinked polymer.

Example 6

Into a three-necked flask, 90mmol of p-terphenyl, 87mmol of indoloquinone, 3mmol of 3-bromo-1, 1-trifluoroacetone and 120mL of methylene chloride were charged. 120mL of trifluoromethanesulfonic acid and 8mL of trifluoroacetic acid are added dropwise and reacted for 24 hours at room temperature. 15g of the dried product is taken and dissolved in DMSO to be crosslinked for 12 hours at 60 ℃, then the product is precipitated out, and the crosslinked polymer is obtained after drying.

Example 7

Into a three-necked flask, 90mmol of p-terphenyl, 83mmol of indoloquinone, 7mmol of 2, 2-trifluoro-4' -Xiuji acetophenone and 150mL of methylene chloride were charged. 135mL of trifluoromethanesulfonic acid and 15mL of trifluoroacetic acid were added dropwise, and the reaction was carried out at room temperature for 48 hours. And then the product is immersed in water, washed and dried. 15g of the dried product is dissolved in DMAc and crosslinked for 24 hours at 80 ℃, and then the product is precipitated out and dried to obtain the crosslinked polymer.

10g of the crosslinked polymer was dissolved in 100mL of NMP, and the mixture was filtered and defoamed to obtain a slurry.

Example 8

Into a three-necked flask, 90mmol of fluorene, 85mmol of indoloquinone, 5mmol of 3-bromo-1, 1-trifluoroacetone and 100mL of methylene chloride were charged. 100mL of trifluoromethanesulfonic acid was added dropwise. The reaction was carried out at-10℃for 24h. And then the product is immersed in water, washed and dried. 15g of the dried product is taken and dissolved in DMSO to be crosslinked for 48 hours at 75 ℃, then the product is precipitated out, and the crosslinked polymer is obtained after drying.

And taking a clean horizontal glass plate, pouring the slurry on the surface of the glass plate, scraping by a scraper, and then placing the glass plate in an oven to dry for 12 hours at 90 ℃ to obtain the micro-crosslinking ionic membrane.

Comparative example 1

Into a three-necked flask, 90mmol of biphenyl, 90mmol of N-methyl-4-piperidone, and 130mL of methylene chloride were charged. 20mL of trifluoroacetic acid and 120mL of trifluoromethanesulfonic acid are added dropwise and reacted for 24 hours at 0 ℃. And then the product is immersed in water, washed and dried. 50g of the dried product is dissolved in DMSO, 50g of MeI is added to react for 24 hours to ionize the product, and the counter ion is I ^- Washing, oven drying, soaking in 1M KOH solution for 24 hr to convert counter ion into OH ^- And cleaning and drying again to obtain the ionized polymer.

10g of the ionized polymer was dissolved in 100mL of DMSO, filtered and defoamed to obtain a slurry.

And taking a clean horizontal glass plate, pouring the slurry on the surface of the glass plate, scraping by a scraper, and then placing the glass plate in an oven to dry at 80 ℃ for 12 hours to obtain the ionic membrane.

The ionic films obtained in examples 1 to 8 and comparative example 1 were tested for tensile strength, elongation at break and swelling ratio, respectively, and the obtained results are shown in Table 1 below.

And respectively testing the tensile strength and the elongation at break of the ionic membrane by adopting a universal tensile testing machine.

Recording the size of the dry ion membrane as R1, putting the dry ion membrane into 1M alkali liquor, fully soaking at 80 ℃, recording the size of the wet ion membrane as R2, and obtaining the swelling ratio of (R2-R1)/R1.

TABLE 1

	Tensile Strength (MPa)	Elongation at break (%)	Swelling Rate (%)
				Comparative example 1	32	37	23
Example 1	40	54	8
				Example 2	39	48	10
Example 3	43	53	7
				Example 4	47	57	4
Example 5	50	17	9
				Example 6	53	15	10
Example 7	55	20	6
				Example 8	49	20	8

As can be seen from Table 1, the ionic membranes of examples 1 to 8 all had significantly improved mechanical strength, significantly increased elongation at break, and decreased swelling compared to comparative example 1.

In addition, the ion films of example 1 and comparative example 1 described above were applied to an electrolytic cell, and the polarization curves shown in fig. 2 were obtained.

The polarization curve is tested as follows:

preparation of catalyst ink: dissolving an ionic crosslinking type ionic membrane in an organic solvent to form a binder; then weighing proper amounts of platinum (Pt)/carbon (C) and iridium oxide dihydrate (IrO) ₂ ) Catalyst (effective loading is 0.5-5mg/cm ² ) Water and isopropyl alcohol solution (the volume ratio of water to isopropyl alcohol is 1:9 to 5: 5) Preparing a catalyst solution as a dispersing agent; and (3) carrying out ultrasonic treatment on the catalyst solution for 20min under the ice bath condition, then adding a proper amount of the ionic crosslinking polymer binder, and mixing and carrying out ultrasonic treatment for 20min to form the uniformly dispersed catalyst ink.

Preparation of a catalyst-supported film: under nitrogen (N) ₂ ) Under the condition of being used as carrier gas, the catalyst ink is uniformly sprayed on the two sides of the ionic crosslinking ionic membrane by using a spray gun on an automatic membrane scraping machine. After the solvent volatilizes, immersing the ionic crosslinking type ionic membrane into a 1M KOH aqueous solution for 48 hours, washing the ionic crosslinking type ionic membrane to be neutral by boiling deionized water to obtain a catalyst supported membrane, and storing the catalyst supported membrane for later use.

Preparation of a membrane electrode assembly: the anode and cathode gas diffusion layers were made of commercially available nickel foam and carbon paper, respectively. The membrane electrode assembly (Membrane Electrode Assembly, MEA) is formed by sandwiching a catalyst-supporting membrane prepared by CCS method (spray coating method) between an anode and a cathode gas diffusion layer, and then closely adhering the catalyst-supporting membrane to both.

Application of the membrane electrode: installing a membrane electrode with an effective area of 1cm multiplied by 1cm in an electrolytic cell test system; circulating 1M KOH solution at 60℃at a rate of 50 mL/min; then at a current density of 1A/cm ^-2 The stability of the cell was tested.

The polarization curve shown in fig. 2 (polarization curve of example 1 is L1, and polarization curve of comparative example 1 is L2) was obtained by the above test. Wherein the abscissa in the polarization curve diagram represents time in hours (h), and the ordinate represents voltage in volts (V).

As can be seen from FIG. 2, the electrolytic cell assembled based on example 1 was at 1A/cm compared with the electrolytic cell assembled based on comparative example 1 ² The operation is stable for 30000 hours, the voltage is not changed obviously, and the excellent stability is shown.

In this embodiment, reference may be made to the above embodiments for description of the crosslinked polymer, the ionic membrane, etc., and the description thereof will be omitted here.

The present application will be described only in connection with the present invention, and the remaining structure may be obtained by referring to the related art, which will not be described in detail herein.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the present application may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims

1. A crosslinked polymer comprising a plurality of polyphenyl units, one polyphenyl unit being reacted with CF by a ketone precursor ₃ -C-B is bonded to another polyphenylic unit, said CF ₃ -C-B is bonded to the nitrogen atom of the group after reaction with the ketone precursor, wherein CF ₃ -C-B is a monomerThe residual structure after the reaction is any one of alkyl, alkoxy, a structure with at least one benzene ring and derivatives thereof, heterocyclic structures and derivatives thereof, and X is a halogen atom;

2. The crosslinked polymer of claim 1, wherein, where the first group is a reacted group of the ketone precursor and a counter ion, the ketone precursor is an N-methyl-4-piperidone monomer;

3. The crosslinked polymer of claim 2, wherein in the case where the ketone precursor is an N-methyl-4-piperidone monomer, the crosslinked polymer has the general structural formula:

n is the molar ratio, and the value of n is between 0 and 0.1;

x is the counter ion.

4. A crosslinked polymer according to claim 3, wherein, in the case where the ketone precursor is an N-methyl-4-piperidone monomer, the crosslinked polymer has the general structural formula:

wherein CF is as follows ₃ -C-B is a monomerAnd the structure remained after the reaction, wherein the B is any one of long alkyl chain with the chain length of 1-10, alkoxy chain with the chain length of 1-10, benzene ring and derivatives thereof, biphenyl and derivatives thereof, pyridine and derivatives thereof, quinoline and derivatives thereof, tropane and derivatives thereof, phenothiazine and derivatives thereof, furan and derivatives thereof.

5. The crosslinked polymer of claim 4 wherein the polymer is a polymer selected from the group consisting ofIncluding 3-bromo-1, 1-trifluoroacetone or 2, 2-trifluoro-4' -Xiuji acetophenone.

6. A binder comprising the crosslinked polymer of any one of claims 1-5, wherein the crosslinked polymer is untreated.

7. An ionic membrane comprising the cross-linked polymer of any one of claims 1-5, wherein the cross-linked polymer is treated.

8. An electrolytic cell comprising an anode, a cathode, and a membrane electrode assembly disposed between the anode and the cathode;

The membrane electrode assembly comprising the binder of claim 6, a catalyst, and the ionic membrane of claim 7, the binder being used to bind the catalyst to the surface of the ionic membrane.

9. A method of preparing an ionic membrane according to claim 7, comprising the steps of:

synthesizing a cross-linked polymer;

preparing the crosslinked polymer into a slurry;

10. The method of preparing an ionic membrane of claim 9, wherein the synthetic cross-linked polymer comprises: